chore: shebang -> /bin/sh, no bash features used

Put shared code in the conditionally compiled `engine::irisawa` module.

README.md

@@ -17,3 +17,51 @@ Note that currently this is just the barest beginnings of the project, more of a
 * Able to run in browser (so implemented in WASM-compatible language)
 
 * Produce scalable graphics of 3D diagrams, and maybe STL files (or other fabricatable file format) as well.
+
+## Prototype
+
+The latest prototype is in the folder `app-proto`. It includes both a user interface and a numerical constraint-solving engine.
+
+### Install the prerequisites
+
+1. Install [`rustup`](https://rust-lang.github.io/rustup/): the officially recommended Rust toolchain manager
+   * It's available on Ubuntu as a [Snap](https://snapcraft.io/rustup)
+2. Call `rustup default stable` to "download the latest stable release of Rust and set it as your default toolchain"
+   * If you forget, the `rustup` [help system](https://github.com/rust-lang/rustup/blob/d9b3601c3feb2e88cf3f8ca4f7ab4fdad71441fd/src/errors.rs#L109-L112) will remind you
+3. Call `rustup target add wasm32-unknown-unknown` to add the [most generic 32-bit WebAssembly target](https://doc.rust-lang.org/nightly/rustc/platform-support/wasm32-unknown-unknown.html)
+4. Call `cargo install wasm-pack` to install the [WebAssembly toolchain](https://rustwasm.github.io/docs/wasm-pack/)
+5. Call `cargo install trunk` to install the [Trunk](https://trunkrs.dev/) web-build tool
+6. Add the `.cargo/bin` folder in your home directory to your executable search path
+   * This lets you call Trunk, and other tools installed by Cargo, without specifying their paths
+   * On POSIX systems, the search path is stored in the `PATH` environment variable
+
+### Play with the prototype
+
+1. Go into the `app-proto` folder
+2. Call `trunk serve --release` to build and serve the prototype
+   * *The crates the prototype depends on will be downloaded and served automatically*
+   * *For a faster build, at the expense of a much slower prototype, you can call `trunk serve` without the `--release` flag*
+3. In a web browser, visit one of the URLs listed under the message `INFO 📡 server listening at:`
+   * *Touching any file in the `app-proto` folder will make Trunk rebuild and live-reload the prototype*
+4. Press *ctrl+C* in the shell where Trunk is running to stop serving the prototype
+
+### Run the engine on some example problems
+
+1. Go into the `app-proto` folder
+2. Call `./run-examples`
+   * *For each example problem, the engine will print the value of the loss function at each optimization step*
+   * *The first example that prints is the same as the Irisawa hexlet example from the Julia version of the engine prototype. If you go into `engine-proto/gram-test`, launch Julia, and then*
+     
+     ```julia
+     include("irisawa-hexlet.jl")
+     for (step, scaled_loss) in enumerate(history_alt.scaled_loss)
+       println(rpad(step-1, 4), " | ", scaled_loss)
+     end
+     ```
+     
+     *you should see that it prints basically the same loss history until the last few steps, when the lower default precision of the Rust engine really starts to show*
+
+### Run the automated tests
+
+1. Go into the `app-proto` folder
+2. Call `cargo test`

app-proto/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 
 [features]
 default = ["console_error_panic_hook"]
+dev = []
 
 [dependencies]
 itertools = "0.13.0"
@@ -36,7 +37,12 @@ features = [
   'WebGlVertexArrayObject'
 ]
 
+# the self-dependency specifies features to use for tests and examples
+#
+#   https://github.com/rust-lang/cargo/issues/2911#issuecomment-1483256987
+#
 [dev-dependencies]
+dyna3 = { path = ".", default-features = false, features = ["dev"] }
 wasm-bindgen-test = "0.3.34"
 
 [profile.release]

app-proto/examples/irisawa-hexlet.rs

@@ -0,0 +1,25 @@
+use dyna3::engine::{Q, irisawa::realize_irisawa_hexlet};
+
+fn main() {
+    const SCALED_TOL: f64 = 1.0e-12;
+    let (config, success, history) = realize_irisawa_hexlet(SCALED_TOL);
+    print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
+    if success {
+        println!("Target accuracy achieved!");
+    } else {
+        println!("Failed to reach target accuracy");
+    }
+    println!("Steps: {}", history.scaled_loss.len() - 1);
+    println!("Loss: {}", history.scaled_loss.last().unwrap());
+    if success {
+        println!("\nChain diameters:");
+        println!("  {} sun (given)", 1.0 / config[(3, 3)]);
+        for k in 4..9 {
+            println!("  {} sun", 1.0 / config[(3, k)]);
+        }
+    }
+    println!("\nStep │ Loss\n─────┼────────────────────────────────");
+    for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
+        println!("{:<4} │ {}", step, scaled_loss);
+    }
+}

app-proto/examples/point-on-sphere.rs

@@ -0,0 +1,38 @@
+use nalgebra::DMatrix;
+
+use dyna3::engine::{Q, point, realize_gram, sphere, PartialMatrix};
+
+fn main() {
+    let gram = {
+        let mut gram_to_be = PartialMatrix::new();
+        for j in 0..2 {
+            for k in j..2 {
+                gram_to_be.push_sym(j, k, if (j, k) == (1, 1) { 1.0 } else { 0.0 });
+            }
+        }
+        gram_to_be
+    };
+    let guess = DMatrix::from_columns(&[
+        point(0.0, 0.0, 2.0),
+        sphere(0.0, 0.0, 0.0, 1.0)
+    ]);
+    let frozen = [(3, 0)];
+    println!();
+    let (config, success, history) = realize_gram(
+        &gram, guess, &frozen,
+        1.0e-12, 0.5, 0.9, 1.1, 200, 110
+    );
+    print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
+    print!("Configuration:{}", config);
+    if success {
+        println!("Target accuracy achieved!");
+    } else {
+        println!("Failed to reach target accuracy");
+    }
+    println!("Steps: {}", history.scaled_loss.len() - 1);
+    println!("Loss: {}", history.scaled_loss.last().unwrap());
+    println!("\nStep │ Loss\n─────┼────────────────────────────────");
+    for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
+        println!("{:<4} │ {}", step, scaled_loss);
+    }
+}

app-proto/examples/three-spheres.rs

@@ -0,0 +1,40 @@
+use nalgebra::DMatrix;
+
+use dyna3::engine::{Q, realize_gram, sphere, PartialMatrix};
+
+fn main() {
+    let gram = {
+        let mut gram_to_be = PartialMatrix::new();
+        for j in 0..3 {
+            for k in j..3 {
+                gram_to_be.push_sym(j, k, if j == k { 1.0 } else { -1.0 });
+            }
+        }
+        gram_to_be
+    };
+    let guess = {
+        let a: f64 = 0.75_f64.sqrt();
+        DMatrix::from_columns(&[
+            sphere(1.0, 0.0, 0.0, 1.0),
+            sphere(-0.5, a, 0.0, 1.0),
+            sphere(-0.5, -a, 0.0, 1.0)
+        ])
+    };
+    println!();
+    let (config, success, history) = realize_gram(
+        &gram, guess, &[],
+        1.0e-12, 0.5, 0.9, 1.1, 200, 110
+    );
+    print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
+    if success {
+        println!("Target accuracy achieved!");
+    } else {
+        println!("Failed to reach target accuracy");
+    }
+    println!("Steps: {}", history.scaled_loss.len() - 1);
+    println!("Loss: {}", history.scaled_loss.last().unwrap());
+    println!("\nStep │ Loss\n─────┼────────────────────────────────");
+    for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
+        println!("{:<4} │ {}", step, scaled_loss);
+    }
+}

app-proto/run-examples

@@ -1,8 +1,11 @@
-# based on "Enabling print statements in Cargo tests", by Jon Almeida
+#!/bin/sh
+
+# run all Cargo examples, as described here:
 #
-#   https://jonalmeida.com/posts/2015/01/23/print-cargo/
+#   Karol Kuczmarski. "Add examples to your Rust libraries"
+#   http://xion.io/post/code/rust-examples.html
 #
 
-cargo test -- --nocapture engine::tests::irisawa_hexlet_test
-cargo test -- --nocapture engine::tests::three_spheres_example
-cargo test -- --nocapture engine::tests::point_on_sphere_example
+cargo run --example irisawa-hexlet
+cargo run --example three-spheres
+cargo run --example point-on-sphere

app-proto/src/engine.rs

@@ -4,7 +4,7 @@ use web_sys::{console, wasm_bindgen::JsValue}; /* DEBUG */
 
 // --- elements ---
 
-#[cfg(test)]
+#[cfg(feature = "dev")]
 pub fn point(x: f64, y: f64, z: f64) -> DVector<f64> {
     DVector::from_column_slice(&[x, y, z, 0.5, 0.5*(x*x + y*y + z*z)])
 }
@@ -113,7 +113,7 @@ impl DescentHistory {
 
 // the Lorentz form
 lazy_static! {
-    static ref Q: DMatrix<f64> = DMatrix::from_row_slice(5, 5, &[
+    pub static ref Q: DMatrix<f64> = DMatrix::from_row_slice(5, 5, &[
         1.0, 0.0, 0.0,  0.0,  0.0,
         0.0, 1.0, 0.0,  0.0,  0.0,
         0.0, 0.0, 1.0,  0.0,  0.0,
@@ -277,12 +277,79 @@ pub fn realize_gram(
 
 // --- tests ---
 
-#[cfg(test)]
-mod tests {
+// this problem is from a sangaku by Irisawa Shintarō Hiroatsu. the article
+// below includes a nice translation of the problem statement, which was
+// recorded in Uchida Itsumi's book _Kokon sankan_ (_Mathematics, Past and
+// Present_)
+//
+//   "Japan's 'Wasan' Mathematical Tradition", by Abe Haruki
+//   https://www.nippon.com/en/japan-topics/c12801/
+//
+#[cfg(feature = "dev")]
+pub mod irisawa {
     use std::{array, f64::consts::PI};
     
     use super::*;
     
+    pub fn realize_irisawa_hexlet(scaled_tol: f64) -> (DMatrix<f64>, bool, DescentHistory) {
+        let gram = {
+            let mut gram_to_be = PartialMatrix::new();
+            for s in 0..9 {
+                // each sphere is represented by a spacelike vector
+                gram_to_be.push_sym(s, s, 1.0);
+                
+                // the circumscribing sphere is tangent to all of the other
+                // spheres, with matching orientation
+                if s > 0 {
+                    gram_to_be.push_sym(0, s, 1.0);
+                }
+                
+                if s > 2 {
+                    // each chain sphere is tangent to the "sun" and "moon"
+                    // spheres, with opposing orientation
+                    for n in 1..3 {
+                        gram_to_be.push_sym(s, n, -1.0);
+                    }
+                    
+                    // each chain sphere is tangent to the next chain sphere,
+                    // with opposing orientation
+                    let s_next = 3 + (s-2) % 6;
+                    gram_to_be.push_sym(s, s_next, -1.0);
+                }
+            }
+            gram_to_be
+        };
+        
+        let guess = DMatrix::from_columns(
+            [
+                sphere(0.0, 0.0, 0.0, 15.0),
+                sphere(0.0, 0.0, -9.0, 5.0),
+                sphere(0.0, 0.0, 11.0, 3.0)
+            ].into_iter().chain(
+                (1..=6).map(
+                    |k| {
+                        let ang = (k as f64) * PI/3.0;
+                        sphere(9.0 * ang.cos(), 9.0 * ang.sin(), 0.0, 2.5)
+                    }
+                )
+            ).collect::<Vec<_>>().as_slice()
+        );
+        
+        // the frozen entries fix the radii of the circumscribing sphere, the
+        // "sun" and "moon" spheres, and one of the chain spheres
+        let frozen: [(usize, usize); 4] = array::from_fn(|k| (3, k));
+        
+        realize_gram(
+            &gram, guess, &frozen,
+            scaled_tol, 0.5, 0.9, 1.1, 200, 110
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{*, irisawa::realize_irisawa_hexlet};
+    
     #[test]
     fn sub_proj_test() {
         let target = PartialMatrix(vec![
@@ -328,181 +395,19 @@ mod tests {
         assert!(state.loss.abs() < f64::EPSILON);
     }
     
-    // this problem is from a sangaku by Irisawa Shintarō Hiroatsu. the article
-    // below includes a nice translation of the problem statement, which was
-    // recorded in Uchida Itsumi's book _Kokon sankan_ (_Mathematics, Past and
-    // Present_)
-    //
-    //   "Japan's 'Wasan' Mathematical Tradition", by Abe Haruki
-    //   https://www.nippon.com/en/japan-topics/c12801/
-    //
     #[test]
     fn irisawa_hexlet_test() {
-        let gram = PartialMatrix({
-            let mut entries = Vec::<MatrixEntry>::new();
-            for s in 0..9 {
-                // each sphere is represented by a spacelike vector
-                entries.push(MatrixEntry { index: (s, s), value: 1.0 });
-                
-                // the circumscribing sphere is tangent to all of the other
-                // spheres, with matching orientation
-                if s > 0 {
-                    entries.push(MatrixEntry { index: (0, s), value: 1.0 });
-                    entries.push(MatrixEntry { index: (s, 0), value: 1.0 });
-                }
-                
-                if s > 2 {
-                    // each chain sphere is tangent to the "sun" and "moon"
-                    // spheres, with opposing orientation
-                    for n in 1..3 {
-                        entries.push(MatrixEntry { index: (s, n), value: -1.0 });
-                        entries.push(MatrixEntry { index: (n, s), value: -1.0 });
-                    }
-                    
-                    // each chain sphere is tangent to the next chain sphere,
-                    // with opposing orientation
-                    let s_next = 3 + (s-2) % 6;
-                    entries.push(MatrixEntry { index: (s, s_next), value: -1.0 });
-                    entries.push(MatrixEntry { index: (s_next, s), value: -1.0 });
-                }
-            }
-            entries
-        });
-        let guess = DMatrix::from_columns(
-            [
-                sphere(0.0, 0.0, 0.0, 15.0),
-                sphere(0.0, 0.0, -9.0, 5.0),
-                sphere(0.0, 0.0, 11.0, 3.0)
-            ].into_iter().chain(
-                (1..=6).map(
-                    |k| {
-                        let ang = (k as f64) * PI/3.0;
-                        sphere(9.0 * ang.cos(), 9.0 * ang.sin(), 0.0, 2.5)
-                    }
-                )
-            ).collect::<Vec<_>>().as_slice()
-        );
-        let frozen: [(usize, usize); 4] = array::from_fn(|k| (3, k));
+        // solve Irisawa's problem
         const SCALED_TOL: f64 = 1.0e-12;
-        let (config, success, history) = realize_gram(
-            &gram, guess, &frozen,
-            SCALED_TOL, 0.5, 0.9, 1.1, 200, 110
-        );
+        let (config, _, _) = realize_irisawa_hexlet(SCALED_TOL);
+        
+        // check against Irisawa's solution
         let entry_tol = SCALED_TOL.sqrt();
         let solution_diams = [30.0, 10.0, 6.0, 5.0, 15.0, 10.0, 3.75, 2.5, 2.0 + 8.0/11.0];
         for (k, diam) in solution_diams.into_iter().enumerate() {
             assert!((config[(3, k)] - 1.0 / diam).abs() < entry_tol);
         }
-        print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
-        if success {
-            println!("Target accuracy achieved!");
-        } else {
-            println!("Failed to reach target accuracy");
     }
-        println!("Steps: {}", history.scaled_loss.len() - 1);
-        println!("Loss: {}", history.scaled_loss.last().unwrap());
-        if success {
-            println!("\nChain diameters:");
-            println!("  {} sun (given)", 1.0 / config[(3, 3)]);
-            for k in 4..9 {
-                println!("  {} sun", 1.0 / config[(3, k)]);
-            }
-        }
-        println!("\nStep │ Loss\n─────┼────────────────────────────────");
-        for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
-            println!("{:<4} │ {}", step, scaled_loss);
-        }
-    }
-    
-    // --- process inspection examples ---
-    
-    // these tests are meant for human inspection, not automated use. run them
-    // one at a time in `--nocapture` mode and read through the results and
-    // optimization histories that they print out. the `run-examples` script
-    // will run all of them
-    
-    #[test]
-    fn three_spheres_example() {
-        let gram = PartialMatrix({
-            let mut entries = Vec::<MatrixEntry>::new();
-            for j in 0..3 {
-                for k in 0..3 {
-                    entries.push(MatrixEntry {
-                        index: (j, k),
-                        value: if j == k { 1.0 } else { -1.0 }
-                    });
-                }
-            }
-            entries
-        });
-        let guess = {
-            let a: f64 = 0.75_f64.sqrt();
-            DMatrix::from_columns(&[
-                sphere(1.0, 0.0, 0.0, 1.0),
-                sphere(-0.5, a, 0.0, 1.0),
-                sphere(-0.5, -a, 0.0, 1.0)
-            ])
-        };
-        println!();
-        let (config, success, history) = realize_gram(
-            &gram, guess, &[],
-            1.0e-12, 0.5, 0.9, 1.1, 200, 110
-        );
-        print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
-        if success {
-            println!("Target accuracy achieved!");
-        } else {
-            println!("Failed to reach target accuracy");
-        }
-        println!("Steps: {}", history.scaled_loss.len() - 1);
-        println!("Loss: {}", history.scaled_loss.last().unwrap());
-        println!("\nStep │ Loss\n─────┼────────────────────────────────");
-        for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
-            println!("{:<4} │ {}", step, scaled_loss);
-        }
-    }
-    
-    #[test]
-    fn point_on_sphere_example() {
-        let gram = PartialMatrix({
-            let mut entries = Vec::<MatrixEntry>::new();
-            for j in 0..2 {
-                for k in 0..2 {
-                    entries.push(MatrixEntry {
-                        index: (j, k),
-                        value: if (j, k) == (1, 1) { 1.0 } else { 0.0 }
-                    });
-                }
-            }
-            entries
-        });
-        let guess = DMatrix::from_columns(&[
-            point(0.0, 0.0, 2.0),
-            sphere(0.0, 0.0, 0.0, 1.0)
-        ]);
-        let frozen = [(3, 0)];
-        println!();
-        let (config, success, history) = realize_gram(
-            &gram, guess, &frozen,
-            1.0e-12, 0.5, 0.9, 1.1, 200, 110
-        );
-        print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
-        print!("Configuration:{}", config);
-        if success {
-            println!("Target accuracy achieved!");
-        } else {
-            println!("Failed to reach target accuracy");
-        }
-        println!("Steps: {}", history.scaled_loss.len() - 1);
-        println!("Loss: {}", history.scaled_loss.last().unwrap());
-        println!("\nStep │ Loss\n─────┼────────────────────────────────");
-        for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
-            println!("{:<4} │ {}", step, scaled_loss);
-        }
-    }
-    
-    /* TO DO */
-    // --- new test placed here to avoid merge conflict ---
     
     // at the frozen indices, the optimization steps should have exact zeros,
     // and the realized configuration should match the initial guess

app-proto/src/lib.rs

@@ -0,0 +1 @@
+pub mod engine;